With little more than Bernard Pietenpol's plans, anybody could build an airplane.

When the aviation editor of Modern Mechanics and Inventions wrote in 1929 that it was not likely that an automobile engine could be adapted for flight, Pietenpol and a friend, Don Finke, flew two of the new “two-place” machines up to Minneapolis on April 14, 1930, to prove him wrong. The editor, Westy Farmer, was won over, and the magazine printed drawings and photographs that publicized the new airplane.

The magazine dubbed the aircraft the “Air Camper,” and the name stuck. A few years later, Pietenpol introduced the single-place Sky Scout, but the Air Camper has remained the overwhelming favorite of builders. Modern Mechanics published a set of Air Camper plans in 1932 in its annual Flying and Glider Manual.

Back in Cherry Grove, an 18-year-old friend of Pietenpol’s, Orrin Hoopman, drafted a second set of plans for the Air Camper in 1934. Pietenpol began selling them—along with instructions on how to convert the Model A engine—for $7.50 a set. Today, builders can order the very same plans for $100 from Pietenpol’s son Don, who says there continues to be a slow but steady demand. Additionally, the store in the Experimental Aircraft Association’s museum at Oshkosh, Wisconsin, sells a reprint of the 1932 Flying and Glider Manual for $6.95.

Bernard Pietenpol spent the rest of his life in Cherry Grove. With the onset of World War II, the demand for Pietenpol kits and plans plummeted. Says Don: “After the war, we ran the shop for a couple of years and almost starved.” His father gave up trying to make money on his aircraft designs and opened a television and radio repair shop. He continued building his own airplanes until 1970, and flew until he was 80. Pietenpol builders continued to make pilgrimages to Cherry Grove to seek his counsel.

Pietenpol died in 1984, at the age of 83. Today, his garage workshop is listed in the National Register of Historic Places. The hangar he built in Cherry Grove has been dismantled and reconstructed next to the EAA’s museum, which has two of his Air Campers in its collection.

Pietenpol’s legacy is an elegant little aircraft that anyone with diligence and modest skills can build with ordinary tools and readily available materials. In fact, that’s the only way you can get one, unless you buy one from someone who has already done the work. For more than 80 years, people have been constructing Piets in barns, hangars, garages, basements, workshops, and living rooms—anywhere they could find space to lay out a jig for the fuselage framework and hang a one-piece wing. (Pietenpol built his first airplanes in an abandoned Lutheran church.)

More than 300 Pietenpols are registered with the Federal Aviation Administration. Perhaps dozens more Pietenpols are under construction. They have been built in Canada, the United Kingdom, Spain, and Brazil, and small but enthusiastic groups can be found in Australia and New Zealand. Recently a Piet was spotted in Russia.

There’s no mistaking a Pietenpol Air Camper: the high parasol wing, boxy fuselage, and angular tail structures. Yet of the hundreds in existence, no two are exactly alike. Pietenpol kept making changes to the Air Camper, and he openly encouraged others to do the same. Says Don: “My dad used to say that he built the best airplane he could, and if somebody can build a better one, go ahead and do it.” (Pietenpol liked improvements, but he wasn’t much for frills. Somebody once said that if the Shakers had built airplanes, they would have looked like Pietenpols.)

The original plans, whether deliberately or not, seem to demand experimenting. “There are a number of places where the plans do not have certain dimensions, and there are other places where the dimensions are actually wrong,” says Doc Mosher, a retired corporate pilot and editor of a newsletter about the Pietenpol. “And we all find this out after a while, and then we all laugh and have a beer and say, ‘Well, that’s why it’s called experimental.’ ”

Some changes, however, have gone too far, fueling the argument over what is and what isn’t a true Pietenpol. “If it wasn’t built from the original plans, it’s not a Pietenpol,” says Don.